State governments continue to move ahead with increased regulation of per- and polyfluoroalkyl substance (PFAS)-related compounds, including recent significant steps by California. On February 6, 2020, California’s State Water Resources Control Board announced that it would reduce response levels (RLs) for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) in drinking water to 10 parts per trillion (ppt) for PFOA and 40 ppt for PFOS. The previous RL was 70 ppt for the total concentration of both substances combined. If a water system contains PFOA or PFOS in excess of the RLs, it must take the water source out of service, treat the source or notify customers in writing. The revised RLs follow recent revisions to California’s PFOA and PFOS notification levels (NLs), which, when exceeded, require notification and further monitoring. The changes are in response to recommendations from the California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) and are part of the increased nationwide scrutiny of PFOA and PFOS. These substances, along with other PFASs, have been used extensively in consumer products, but there are studies indicating that exposure above certain levels can have adverse health effects. The State Water Resources Control Board has requested OEHHA’s recommendation in developing NLs for additional PFAS compounds, and the state is also developing Public Health Goals (PHGs) that will set the concentrations for PFOA and PFOS in drinking water that are deemed to pose no significant health risks.